During the past 20 years, various criteria have evolved for evaluating health screening procedures. To date, these criteria have been fairly broadly applied to various chemical laboratory determinations, electrocardiography, radiography, cervical cytology and other screening tests. It has long been clear to physicians that the medical history can also have an important role in screening for disease. In particular, that portion of the physician's history-taking process known as the review of symptoms has become a primary means for revealing undetected medical conditions. This research study is considering the value of the medical history question in clinical and pre-clinical screening for disease states. There is some evidence which indicates that such questions can serve as useful screening tests, for both the basically-well and for the hundreds of thousands of patients seen each day in medical offices, clinics, etc. To establish criteria for measuring the effectiveness of the medical history question in screening for disease states, the following parameters used for evaluating other screening tests are being studied: validity, reliability, yield, availability of follow-up services, importance of the disease and success of treatment. It is believed that improved techniques for the assessment of individual medical history questions will result in the elimination of inappropriate questions and in the addition of more suitable queries in routine health screening evaluation.